1. Field of the Invention
The present invention pertains to a bearing retainer that holds a bearing in place in a bearing seat of an electromagnetic device where the bearing retainer has a unique construction that reduces its cost of manufacture. More specifically, the present invention pertains to a bearing retainer having a flanged shaped outer peripheral edge with a plurality of radially extending tabs centered in gaps in the peripheral edge. The flanged shape of the peripheral edge enables the retainer to be bowl/track fed in automated assembly of the retainer into a housing and the tabs connect with tabs of adjacent bearing retainers, allowing optimization of material consumption and reducing costs in the stamping process. In the preferred embodiment, the bearing retainers are composed of a pre-tempered steel, for example Martinsite.RTM., thus eliminating a subsequent heat tempering process required of prior art retainers and further reducing the cost of manufacture.
2. Description of the Related Art
A bearing retainer is employed to retain a bearing supporting a rotating shaft of a device in a bearing seat on an enclosure end wall of the device. An example of such a bearing retainer is described in the U.S. Pat. No. 4,910,424, of Borcherding, which is assigned to the assignee of the present invention and is incorporated herein by reference.
The prior art bearing retainer disclosed in the above referenced patent is manufactured by stamping the retainer from a strip of steel. The stamped retainer has a center hole, defined by a circular inner edge of the bearing, and a circular outer perimeter. The bearing has an intermediate ring section between the inner edge and the outer perimeter of the bearing. The ring section is generally flat and is pressed flat against a mating surface or surfaces of the device enclosure end wall when inserting the retainer against a bearing positioned in the bearing seat of the end wall. The outer perimeter edge of the retainer is formed at an angle relative to the intermediate ring section of the retainer. This provides a chamfer or tapered edge around the outer perimeter of the bearing retainer that is press-fit into an annular cavity or shoulder of the device enclosure end wall to securely hold the bearing retainer in position in the end wall. A plurality of resilient fingers project radially inwardly from the inner edge of the bearing retainer into the retainer center hole. The fingers are also angled relative to the intermediate ring section of the bearing. The resilient fingers engage against the outer surface of the bearing mounted in the bearing seat of the device enclosure end wall and hold the bearing in the bearing seat.
As stated earlier, prior art bearing retainers of this type are manufactured by stamping the bearing retainer from a strip of steel. In the stamping process, the bearing retainer is cut out from the strip of steel in its final configuration and is simultaneously formed with its tapered outer edge and with the plurality of angled, resilient fingers spatially arranged around its inner edge. Subsequent to the stamping process, the bearing retainer is heat tempered to increase its strength. Although the bearing retainer of the prior art functions well for its intended purpose, it could be improved upon if its manufacturing costs are reduced.